FNTB and breast cancer: According to the multivariate Cox regression analysis in the total cohort, adjusted for established breast cancer risk factors (i.e., age, tumour size, histopathological grading, histology, ER- PR- and HER2 receptor status and breast cancer subtype; see Supplementary Tables S1–S3) we observed that the FNTB-173 6G > 5G polymorphism was an independent predictor of all the outcome parameters investigated (RFI: HR = 0.568, 95% CI = 0.339–0.949, p = 0.031; OS: HR = 0.629, 95% CI = 0.403–0.980, p = 0.040; BCSS: HR = 0.433, 95% CI = 0.231–0.882, p = 0.021; Table 1).